Optical polarization and anisotropic gain characteristics in semipolar and nonpolar InGaN quantum well lasers



By using a new simple theoretical approach, the previously-reported experimental results of the polarization properties in semipolar and nonpolar InGaN quantum wells (QWs) were analyzed. On the basis of the k·p-perturbation theory, we derived a useful analytical expression for describing the polarization properties of these QWs, and used this expression to analyze experimental data reported from various research groups. All the reported data are successfully fitted by the analytical expression, and realistic prediction of polarization properties is possible for unexplored substrate orientation and In composition. Based on these analyses, it is predicted that the optical gain characteristics favourable for laser diodes with cleaved-facet cavity mirrors would appear in the green-InGaN QWs on the lower-angle semipolar planes (30° ∼ 40° inclined from the c-plane). (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)